Which is true for an element R present in group 13 of the periodic table

detailed solution

Correct option is C

All 13th group elements are solids at room temperature ,except "Ga" ,Ga exist as liquid at room temperature .→ 13th group elements maximum oxidation state is +3 due to the presence of three valence electrons in their valency shell.→ 13th group elements forms the oxides with the formula M2O3 [ R2O3 ].→ 13th group elements forms the halides with the formula MX3 [RX3],since their valency is three ,therefore they will combine with three halogen atoms.For writing formula of the compound we need to follow above shown CRISS-CROSS METHOD.